Synchronizing mechanism for photographic cameras adapted to use mechanically fired flash lamps

ABSTRACT

A photographic camera is provided with a three-legged member which rotates rapidly upon release to synchronize several or all of the following operations: A. INITIATION OF AUTOMATIC EXPOSURE CONTROL FUNCTIONING; B. ACTUATION OF THE CAMERA SHUTTER; C. DISPLACEMENT OF THE VIEWER MIRROR (SINGLE LENS REFLEX CAMERAS) FROM THE CAMERA&#39;&#39;S OPTICAL PATH; AND D. ACTUATION OF A PERCUSSIVELY IGNITABLE FLASHLAMP. The three-legged member is energized prior to picture-taking and release is accomplished when the camera user depresses or otherwise actuates the camera release member.

United States Patent Ettischer 1 Sept. 12, 1972 3,584,551 6/1971 Dierkset al. ..95/l1.5 R X Primary ExaminerSamuel S. Matthews AssistantExaminer-Michael L. Gellner Attorney-Robert W. Hampton and Leonard W.

[72] Inventor: Helmut Ettischer, Stuttgart-Wagen, Germany [731 Assignee:Eastman Kodak Company, Roches- [57] ABSTRAeT L A photographic camera isprovided with a three- [22] Filed: 19, 1970 legged member which rotatesrapidly upon release to synchronize several or all of the followingoperations: PP N05 65,034 a. initiation of automatic exposure controlfunctioning;

52 U.S.Cl ..9s/11.s, 95/42 actuation Ofthe camerashufier;

[51] Int. Cl. ..G03b 15/04 displacement of the viewer mirror (Singlelens [58] Field of Search ..95/11.5 R, 42 reflex cameras) from thecameras p a p v v and [56] Rgferences Cit d d. actuation ofapercussively ignitable flashlamp.

UNITED STATES PATENTS The three-legged member is energized prior topicture-taking and release is accomplished when the 2,322,734 6/1943Steiner ..95/42 camera user depresses or otherwise actuates the 222:24:22: mesa-,1

2,956,490 10/1960 StaudtH ..95/42 x 3,254,584 6/1966 Okajima ..95/42 2Claims 6 Drawing Figures 0 I0 I00 I2 40 lOb l W I. l'

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PATENTEB EPIZ m2 3.690.236

sumaura HELMUT ETTISCHER INVENTOR ATTORNEYS CROSS-REFERENCE TO RELATEDAPPLICATION Reference is made to commonly -assigned..U.S.applicationSer. No. 765,926,now=U.S.-.Pat. No..3,576,=l55g entitledPercussion Activatable-FIash Units I-IavingIndividual-Striker Elementsand Photographic Apparatus v for UsingSuchUnits filed Oct. 8;, 1968,:inthename-of 1 David E. Beach and copending ;=U.S.. application-Set.

No. 10,068 filed Feb. 12, 1970, entitIed;:PI-IOTO-. GRAPHIC APPARATUS,DavidN. Brooks.-

I BACKGROUND or THE INVENTION 1.. Fieldof the Invention I The presentinvention. relates to photographic. cameras and camera mechanismsusablevwith. mechani-. cally; ignitable flash lamps and morev particularly, to

operations with the actuation of mechanically ignitable flash lamps, forexample, percussively ignitable flash. I lamps. I

2. Description of the BriorArt. his well known in the photographic artto .use electri-.

cally fired flash devices to supplementthe natural light available forpicture taking. While electrically fired flashdevices have provided:generally satisfactory results it has proven difficult to design firingsystems whichhave the highreliability desirable in thisapplicav tion. i

The batteries which typically, serve as the power sourceinelectricalflash firing systems deteriorate with age and usereducing'their effectiveness in. initiating flash operation. The contactsurfaces-of the electrical circuit are subject to corrosionwhichrfurther-serves to render the firing system less dependable. Theexasperating quality of a: flash failure because-of either or acombination of the above causes.isaccentuated when the failure occursfor a-once in a lifetime'picture taking opportunity. In order tomaintain a users satisfaction with his camera, it is desirable that thelikelihood of such flash failures be minimized.

- To obviatethe need for electrical power sources and circuits and toprovide for more dependable flash photography, percussively ignitableflash lamps have been developed. I I

' One such lamp is disclosed in US. application Ser. No. 765,926entitled PERCUSSION ACTIVATABLE FLASH UNITS HAVING INDIVIDUAL ST RIKERELEMENTS AND PHOTOGRAPHIC APPARATUS FOR USING SUCH UNITS filed Oct. 8,1968, in the name of David E. Beach, and now US. Pat No. 3,576,166.

In this application a percussively ignitable flash lamp is disclosedthat can be assembled in a unit with a percussion striker which is heldin a pre-energized condition by a latch member releasable to effectignition of the lamp.

A multilamp flash unit of a similar type is described below whereinpercussively ignitable' flash lamps are supported so as to be fireableby pre-energized spring striker members. Actuation of the flash unit isaccomplished when an actuating bar or probe enters a striker accessopening for the lamp in firing position engaging and'dislodging thestriker member.

mechan'isms for synchronizingessential picture-taking In US. Pat. No.2,972,937 (Suits) it is suggested that a flash lampcan I be ignited bypiezo-electrical actuation, that is, by striking a piezo electricalelement locatedeither in the camera or theflashlamp unit and Ielectrically connected tothe lamp.

posingoperations.

U.S..application Ser. No. 10,068filed Feb. 12, 1970,,

entitled ,PIIOTOGRAPI-IIC APPARATUS IfiIedin the I nameof David N.Brooks, discloses a springener gi zed driver, released for movementthrough apath' supplying theenergy forfiring a percussive lamp andreleasin'ga".

shutter driver in timed relation.

,- Although suchamechanism is acceptable for relatively. simple cameras,with more complex cameras I such-assingle lens reflex, cameras, furtherfunctions must .be accomplished. I

Forexample, it is widely known to use central open; ingshutters having acontrol-shaft which extends externally to the shutter housing topermitsynchronization I ofv the shutter with other cameradevices,Ashutter mechanismincluding such a control shaft is described inGermanPat. No. 1,115,574. When the viewing mir- I'OI'Ofifi single lens reflexcamera mustbe moved and a flash actuatedv mechanically, the synchronizatipn problems multiply.

SUMMARY OF THE INVENTION The present invention, provides a camera with apreenergizede rotatable synchronizing. member which moves rapidlyuponrelease throughan operative path to serve in coordinating known filmexposing operations and, actuation of a flash device employing Imechanically ignitable flash lamps.

According to a preferred embodiment of the invention, a multi-leggedrotatingpre-energizedsynchronizing member coordinates the more numerousfilm exposing operations encountered with sophisticated cameras such asshutter'actuation, mirror movement and exposure control in single lensreflex cameras. A

BRIEF DESCRIPTION OF THE DRAWING The following figures are referred toin the detailed description of the presently preferred embodiment of theinvention.-

FIG. 1 is a front elevational view of a camera with tion of the cameraelements with a picture taking sequence partially completed. I

FIG. 4 is a plan view of a camera with portions removed for clarity inillustrating the present invention. FIG. 5 is a perspective view of amultilamp flash unit utilizing percussively ignitable flash lampsillustrating the elements in their positions prior to actuation.Portions have been removed to illustrate more clearly the position ofthose elements related to the present invention.

FIG. 6 corresponds to FIG. but illustrates the position of the elementsat the time of flash lamp ignition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Because photographic cameras arewell known, the present description will be directed in particular toelements forming part of, or cooperating more directly with, apparatusin accordance with the present invention. It is to be understood thatcamera elements not specifically shown or described may take variousforms well known to those skilled in the art. v

Referring to FIGS. 1-4, a portion of a single lens reflex camera isshown. The camera includes a prin-' cipal optical path shownschematically in FIGS. 1-3 as partially defined by a'shutter 2. Acrossthe principal optical path is amovable mirror 'for reflecting light to aviewfinder pentaprism 12. A flashcube socket 4a is positioned to receivea flashcube actuatable by strucarms, 16b, 16c and 1611, is released by alatch 41 and rotates rapidly about a pivot point 17 in the direction ofan arrow D under the urging of a tension spring 15. The rotation ofthree-armed spider member 16 is transmitted to a mirror latch 18 by arm16b which includes a recess in which a pin 18a of mirror latch 18 rides.Mirror latch 18 is slidably mounted to move in a vertical path andoperative rotation of arm 16b is translated into a downward motion ofmirror latch 18. A mirror latch pin 18b while in a pre-operativeposition engages a latch arm 19 which is rigidly attached to the springbiased mirror 20. With latch arm 19 restrained by latch pin 18b mirror20 is maintained in viewing position wherein the camera-operator isenabled to view the scene to be recorded in the viewfinder 12 through awindow 11 and an eyepiece 13 (shown in FIG. 4).

At a pre-selected rotation of three-armed lever 16, mirror latch 18 istranslated sufficiently for latch pin 18b to move beyond latch arm 19.With latch pin 18b no longer engaging latch arm 19, spring biased mirror20 is free-to flip to the exposure position (illustrated in FIG. 3).

Rotation of three-armed spider member 16 is further transmitted to arack bar 21 by means of arm 16c. Rack bar 21 is slidably mounted to movein a horizontal path and is driven in a picture. taking direction A by ahorizontal force component transmitted to a rack bar pin 21a throughengagement with arm 160. A pinion 22 engages a toothed portion 21a ofbar 21 and is fastened to rotate with a control shaft 22a. Operativehorizontal movement of rack bar 21 is thus translated by pinion 22 intoa rotation of control shaft 22a. Initial rotary motion of control shaft22a causes an automatic diaphragm (not shown) of the objective lens tobe adjusted to the exposure value determined'by an exposure controldevice sensitive to scene illumiation as is common in single lens reflexcameras. At the end of this motion control shaft 22a releasespretensioned shutter 2 to effect film exposure. During a cameraoperation performed without a flash unit mounted on the camera, thethird lever arm 16d which effects actuation of the photoflash unit asdescribed below has no role in the exposure sequence.

After use the synchronizing member 16 may be cocked by manual movementof rack 21, for example, through a drive train connected to a film windmechanism, not shown, to rotate the synchronizing member in acounterclockwise direction until engaged and retained by latch 41.Referring to FIG. 5, a flash unit suitable for use with the presentinvention is illustrated. Flashbulbs 23 consist of a transparentenvelope 24 containing the combustible flash material and a combustionpromoting gas connecting with an ignition pin 25 which projects from thebottom of the bulb and is ignitable by percussion impact. The ignitionpin 25 could be replaced by a piezo electrical element electricallyconnected to the lamp, but also actuable by strik- Several of theseflashbulbs 23 are shown embedded in a base 9 to form a flash unit. Eachflashbulb 23 is associatedv with a spring striker element 26 which isretained in a groove 9a of base 9 and which is pre-ene'rgized, by.torsion in such a manner that oneof its ends 26a is located behind theother end 26b. Spring end 26a extends approximately parallel to thesurface of base 9 and projects beyond an access opening 9b which isprovided at an appropriate position in base 9 with respect to ignitionpin 25. The unit is actuated when an ignition slide bar 6 or probedislodges end 26a from behind end 26b and the stored spring energycauses end 260 to move sharply against ignition pin 25.

Referring to FIG. 2 a flashcube has been inserted into flashcube socket4a and a pin 4 which is associated with the flashcube socket is forceddownwardly driving against one end of a pivoted holding lever 5 whichrocks in a counterclockwise direction against a spring bias. Holdinglever 5 is thus withdrawn from restraining engagement with a pin 60 ofslide bar 6. Ignition slide bar 6 is then free to move upwardly underthe urging of a relatively weak spring 7 until the upper end of.ignition slide bar 6 engages but does not dislodge spring striker end26a. In the course of this movement, a cam follower 6a of ignition slidebar 6 is moved into the path of a cam element 16a disposed at the end oflever arm 16d. Ignition slide bar 6 is thus positioned'to play anoperation of the camera is effected in the same manner as described withreference to FIG. 1; the only difference being that during the pivotalmotion of threearmed spider member 16 ignition slide bar or probe 6 ispushed upwardly in the direction of arrow C by the action of cam elementl6a engaging cam follower 6a, (as shown in'FIG. 3). Slide bar 6 drivesend 26a of spring striker element 26 which is lifted over or dislodgedfrom end 26b and stored spring energy causes end 26a to move sharplyagainst ignition pin 25 actuating flashbulb 24. Rapid movement ofthree-armed spider member 16 assures that percussion firing of theflashbulb takes place in synchronization with shutter action.

Referring to FIGS. 1 and 4, the user in composing his picture, views thescene via an optical path through eyepiece 13, window 11, pentaprism 12to mirror 20 andthe objective lens (not shown). Without a flash unitmounted, a signal lever remains in a spring biased position (as shown inFIG. 1) not visible to the camera user.

With a flash unit mounted, pin 4 is driven against springbiased holdinglever 5 which rocks to the flash position illustrated in FIG. 2. In thiscondition lever 5 no longer engages ignition slide bar 6 which is thenfree to move upwardly under the urging of spring 7. Upward movement ofslide bar 6 is arrested by engaging spring end 26a (as shown in FIG. 5)and signal lever 10 remains in the normal position. For the conditionwherein a used flash lamp is in the firing position, spring end 26a islocated adjacent to the flash lamp (illustrated in FIG. 6) and does notengage slide bar 6. For this condition slide bar 6 is free to moveupwardly until pin 6b engages signal lever 10. Force from spring 7 istransmitted to a control arm 10b of signal lever 10 by a pin 6b of slidebar 6 causing signal lever 10 to rock about a pivot 10a. Signal lever 10thus urged by spring 7 rocks to signal position (illustrated in FIG. 3)wherein signalend 10c moves into the users viewing path and'is thusvisible through window 11 to indicate the condition of the flash lamp tothe user.

The invention has been described in detail with particular reference toa preferred embodiment thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

Iclaim: Y

1. In a camera having a principal optical path, a shutter, a mirrormovable between an exposure position out of said optical path and aviewing position in said optical path and a camera release leveractuatable for initiating a camera picture-taking operation, theimprovement comprising:

means on said camera for releasably receiving a mechanically actuableflash unit; a synchronizing member rotatably mounted in said camera andhaving first, second and third surfaces; means for rotating saidsynchronizing member in response to actuation of said camera releaselever; means located for cooperation with said first surface duringrotation of said synchronizing member for actuating a flash unitreceived in said receiving means; means located for cooperation withsaid second surface during rotation of said synchronizing member formoving said mirror from said viewing position to-said exposure position;and means located for cooperation with said third surface duringrotation of said synchronizing member for actuating said shutter.

2. The invention defined in claim 1 wherein said flash unit actuatingmeans is movable to a first position for cooperating with saidsynchronizing member from a second position out of cooperative relationwith said synchronizing member in response to insertion of a

1. In a camera having a pRincipal optical path, a shutter, a mirrormovable between an exposure position out of said optical path and aviewing position in said optical path and a camera release leveractuatable for initiating a camera picture-taking operation, theimprovement comprising: means on said camera for releasably receiving amechanically actuable flash unit; a synchronizing member rotatablymounted in said camera and having first, second and third surfaces;means for rotating said synchronizing member in response to actuation ofsaid camera release lever; means located for cooperation with said firstsurface during rotation of said synchronizing member for actuating aflash unit received in said receiving means; means located forcooperation with said second surface during rotation of saidsynchronizing member for moving said mirror from said viewing positionto said exposure position; and means located for cooperation with saidthird surface during rotation of said synchronizing member for actuatingsaid shutter.
 2. The invention defined in claim 1 wherein said flashunit actuating means is movable to a first position for cooperating withsaid synchronizing member from a second position out of cooperativerelation with said synchronizing member in response to insertion of aflash unit in said receiving means.